Class: Roby::Queries::TaskMatcher

Inherits:
PlanObjectMatcher show all
Includes:
DRoby::V5::Queries::TaskMatcherDumper
Defined in:
lib/roby/queries/task_matcher.rb,
lib/roby/droby/enable.rb

Overview

This class represents a predicate which can be used to filter tasks. To filter plan-related properties, use Query.

A TaskMatcher object is a AND combination of various tests against tasks.

For instance, if one does

matcher = TaskMatcher.new.which_fullfills(Tasks::Simple).pending

Then

matcher === task

will return true if task is an instance of the Tasks::Simple model and is pending (not started yet), and false if one of these two characteristics is not true.

Direct Known Subclasses

Query

Constant Summary collapse

PLAN_PREDICATES = 
{
    mission_task?: :mission_tasks,
    permanent_task?: :permanent_tasks
}.freeze

Instance Attribute Summary collapse

Attributes inherited from PlanObjectMatcher

#children, #indexed_neg_predicates, #indexed_predicates, #instance, #model, #owners, #parents, #scope

Attributes inherited from MatcherBase

#neg_predicates, #predicates

Class Method Summary collapse

Instance Method Summary collapse

Methods included from DRoby::V5::Queries::TaskMatcherDumper

#droby_dump

Methods inherited from PlanObjectMatcher

#executable?, #global_scope, #global_scope?, #handle_parent_child_match, #local_scope, #local_scope?, #matches_child_constraints?, #matches_parent_constraints?, #not_self_owned, #owned_by, #self_owned, #with_child, #with_instance, #with_model, #with_parent

Methods included from DRoby::V5::Queries::PlanObjectMatcherDumper

#droby_dump

Methods inherited from MatcherBase

declare_class_methods, #describe_failed_match, #each, #match, match_predicate, match_predicates, #reset, #to_a, #to_set

Constructor Details

#initialize ⇒ TaskMatcher

Initializes an empty TaskMatcher object



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# File 'lib/roby/queries/task_matcher.rb', line 43

def initialize
    super
    @arguments = {}
    @indexed_query = !@instance
    @plan_predicates = Set.new
    @neg_plan_predicates = Set.new
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(m, *args) ⇒ Object 



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# File 'lib/roby/queries/task_matcher.rb', line 543

def method_missing(m, *args)
    m_string = m.to_s
    return super unless m_string.end_with?("_event")

    event_name = m[0..-7]
    model = find_event(event_name)
    if !model
        task_models = @model.empty? ? [Roby::Task] : @model
        raise NoMethodError.new(m),
              "no event '#{event_name}' in match model "\
              "#{task_models.map(&:to_s).join(', ')}, use "\
              "#which_fullfills to narrow the task model"
    elsif !args.empty?
        raise ArgumentError,
              "#{m} expected zero arguments, got #{args.size}"
    end

    TaskEventGeneratorMatcher.new(self, event_name)
end

Instance Attribute Details

#arguments ⇒ Hash (readonly)

Set of arguments that should be tested on the task

Returns:

  • (Hash) 


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# File 'lib/roby/queries/task_matcher.rb', line 25

def arguments
  @arguments
end

#neg_plan_predicates ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Set of predicates specific to the plan (e.g. mission/permanent)



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# File 'lib/roby/queries/task_matcher.rb', line 40

def neg_plan_predicates
  @neg_plan_predicates
end

#plan_predicates ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Set of predicates specific to the plan (e.g. mission/permanent)



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# File 'lib/roby/queries/task_matcher.rb', line 35

def plan_predicates
  @plan_predicates
end

Class Method Details

.match_indexed_predicate(name, index: name.to_s, neg_index: nil, not_index: nil, not_neg_index: name.to_s) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/roby/queries/task_matcher.rb', line 172

def match_indexed_predicate(
    name,
    index: name.to_s, neg_index: nil,
    not_index: nil, not_neg_index: name.to_s
)
    method_name = name.to_s.gsub(/\?$/, "")
    class_eval <<~PREDICATE_METHOD, __FILE__, __LINE__ + 1
        def #{method_name}
            add_predicate(:#{name})
            #{"add_indexed_predicate(:#{index})" if index}
            #{"add_indexed_neg_predicate(:#{neg_index})" if neg_index}
            self
        end
        def not_#{method_name}
            add_neg_predicate(:#{name})
            #{"add_indexed_predicates(:#{not_index})" if not_index}
            #{"add_indexed_neg_predicate(:#{not_neg_index})" if not_neg_index}
            self
        end
    PREDICATE_METHOD
    declare_class_methods(method_name, "not_#{method_name}")
end

.match_indexed_predicates(*names) ⇒ Object 



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# File 'lib/roby/queries/task_matcher.rb', line 195

def match_indexed_predicates(*names)
    names.each do |n|
        unless Index::PREDICATES.include?(n)
            raise ArgumentError,
                  "#{n} is not declared in Index::PREDICATES. Use "\
                  "match_indexed_predicate directly to override "\
                  "this check"
        end

        match_indexed_predicate(n)
    end
end

Instance Method Details

#&(other) ⇒ Object

Computes the intersection of two predicates

The returned task matcher will yield tasks that are matched by all the elements.

Roby does only supports computing the AND of task matchers (cannot combine different operators)



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# File 'lib/roby/queries/task_matcher.rb', line 630

def &(other)
    result = AndMatcher::Tasks.new
    result << self
    case other
    when AndMatcher::Tasks
        result.merge(other)
    when TaskMatcher
        result << other
    else
        raise ArgumentError,
              "cannot compute the intersection of a TaskMatcher with #{other}"
    end
end

#===(task) ⇒ Object

True if task matches all the criteria defined on this object.



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# File 'lib/roby/queries/task_matcher.rb', line 424

def ===(task) # rubocop:disable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
    return unless task.kind_of?(Roby::Task)
    return unless task.arguments.slice(*arguments.keys) == arguments
    return unless super
    return unless (plan = task.plan)
    return unless @plan_predicates.all? { |pred| plan.send(pred, task) }
    return if @neg_plan_predicates.any? { |pred| plan.send(pred, task) }

    true
end

#abstract? ⇒ Object

:method: not_finishing

Matches if the task is not finishing

See also #finishing, Task#finishing?



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# File 'lib/roby/queries/task_matcher.rb', line 335

match_predicates(
    :abstract?, :partially_instanciated?, :fully_instanciated?,
    :interruptible?
)

#add_indexed_neg_predicate(name) ⇒ Object 



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# File 'lib/roby/queries/task_matcher.rb', line 164

def add_indexed_neg_predicate(name)
    return if @indexed_neg_predicates.include?(name)

    @indexed_neg_predicates << name
end

#add_indexed_predicate(name) ⇒ Object 



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# File 'lib/roby/queries/task_matcher.rb', line 160

def add_indexed_predicate(name)
    @indexed_predicates << name unless @indexed_predicates.include?(name)
end

#add_neg_plan_predicate(predicate) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Helper to add a plan predicate in the match set



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# File 'lib/roby/queries/task_matcher.rb', line 369

def add_neg_plan_predicate(predicate)
    if !PLAN_PREDICATES.key?(predicate)
        raise ArgumentError, "unknown plan predicate #{predicate}"
    elsif @plan_predicates.include?(predicate)
        raise ArgumentError, "trying to match #{predicate} & not_#{predicate}"
    end

    @neg_plan_predicates << predicate
    self
end

#add_neg_predicate(name) ⇒ Object 



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# File 'lib/roby/queries/task_matcher.rb', line 154

def add_neg_predicate(name)
    @indexed_query = false unless Index::PREDICATES.include?(name)

    super
end

#add_plan_predicate(predicate) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Helper to add a plan predicate in the match set



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# File 'lib/roby/queries/task_matcher.rb', line 355

def add_plan_predicate(predicate)
    if !PLAN_PREDICATES.key?(predicate)
        raise ArgumentError, "unknown plan predicate #{predicate}"
    elsif @neg_plan_predicates.include?(predicate)
        raise ArgumentError, "trying to match #{predicate} & not_#{predicate}"
    end

    @plan_predicates << predicate
    self
end

#add_predicate(name) ⇒ Object 



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# File 'lib/roby/queries/task_matcher.rb', line 148

def add_predicate(name)
    @indexed_query = false unless Index::PREDICATES.include?(name)

    super
end

#each_in_plan(plan, &block) ⇒ Object

Enumerate the objects matching self in the plan

This resolves the query only the first time. After the first call, the same set of tasks will be returned. Use MatcherBase#reset to clear the cached results.



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# File 'lib/roby/queries/task_matcher.rb', line 585

def each_in_plan(plan, &block)
    return enum_for(__method__, plan) unless block_given?

    evaluate(plan).each_in_plan(plan, &block)
end

#evaluate(plan) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Resolves or returns the cached set of matching tasks in the plan

This is a cached value, so use MatcherBase#reset to actually recompute this set.

This should not be called directly. Use #each_in_plan



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# File 'lib/roby/queries/task_matcher.rb', line 576

def evaluate(plan)
    plan.query_result_set(self)
end

#filter(initial_set, index, initial_is_complete: false) ⇒ Object

Deprecated.

use #filter_tasks_sets instead



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# File 'lib/roby/queries/task_matcher.rb', line 482

def filter(initial_set, index, initial_is_complete: false)
    Roby.warn_deprecated "TaskMatcher#filter is deprecated, "\
                         "use {#filter_tasks_sets} instead"
    filter_tasks_sets(initial_set, index,
                      initial_is_complete: initial_is_complete)
end

#filter_tasks_sets(initial_set, index, initial_is_complete: false) ⇒ ([Set],[Set])

Filters tasks from an initial set to remove as many not-matching tasks as possible

If #indexed_query? is true, the result is required to be exact (i.e. return exactly all tasks in initial_set that match the query)

Parameters:

Returns:

  • (([Set],[Set])) —

    a list of ‘positive’ sets and a list of ‘negative’ sets. The result is computed as positive.inject(&:&) - negative.inject(&:|)



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# File 'lib/roby/queries/task_matcher.rb', line 500

def filter_tasks_sets(initial_set, index, initial_is_complete: false)
    positive_sets, negative_sets = indexed_sets(index)
    if !initial_is_complete || positive_sets.empty?
        positive_sets << initial_set
    end

    negative = negative_sets.shift || Set.new
    unless negative_sets.empty?
        negative = negative.dup
        negative_sets.each { |set| negative.merge(set) }
    end

    positive_sets = positive_sets.sort_by(&:size)

    result = Set.new
    result.compare_by_identity
    positive_sets.shift.each do |obj|
        next if negative.include?(obj)

        result.add(obj) if positive_sets.all? { |set| set.include?(obj) }
    end
    result
end

#find_event(event_name) ⇒ Object 



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# File 'lib/roby/queries/task_matcher.rb', line 524

def find_event(event_name)
    event_name = event_name.to_sym
    models = if !@model.empty?
                 @model
             else
                 [Roby::Task]
             end
    models.each do |m|
        if m.find_event(event_name)
            return TaskEventGeneratorMatcher.new(self, event_name)
        end
    end
    nil
end

#handle_parent_child_arguments(other_query, relation, relation_options) ⇒ Object

Helper method for #with_child and #with_parent



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# File 'lib/roby/queries/task_matcher.rb', line 405

def handle_parent_child_arguments(other_query, relation, relation_options)
    if !other_query.kind_of?(TaskMatcher) && !other_query.kind_of?(Task)
        if relation.kind_of?(Hash)
            arguments = relation
            relation = arguments.delete(:relation) ||
                       arguments.delete("relation")
            relation_options =
                arguments.delete(:relation_options) ||
                arguments.delete("relation_options")

        else
            arguments = {}
        end
        other_query = TaskMatcher.which_fullfills(other_query, arguments)
    end
    [relation, [other_query, relation_options]]
end

#indexed_query? ⇒ Boolean

Returns true if filtering with this TaskMatcher using #=== is equivalent to calling #filter() using a Index. This is used to avoid an explicit O(N) filtering step after filter() has been called

Returns:

  • (Boolean) 


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# File 'lib/roby/queries/task_matcher.rb', line 438

def indexed_query?
    @indexed_query
end

#indexed_sets(index) ⇒ (Set,Set)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Resolve the indexed sets needed to filter an initial set in #filter

Returns:

  • ((Set,Set)) —

    the positive (intersection) and negative (difference) sets. The result will be computed as

    positive.inject(&:&) - negative.inject(&:|)



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# File 'lib/roby/queries/task_matcher.rb', line 449

def indexed_sets(index)
    positive_sets = []
    @model.each do |m|
        positive_sets << index.by_model[m]
    end

    @owners.each do |o|
        candidates = index.by_owner[o]
        return [Set.new, Set.new] unless candidates

        positive_sets << candidates
    end

    @indexed_predicates.each do |pred|
        positive_sets << index.by_predicate[pred]
    end

    negative_sets =
        @indexed_neg_predicates
        .map { |pred| index.by_predicate[pred] }

    @plan_predicates.each do |name|
        positive_sets << index.send(PLAN_PREDICATES.fetch(name))
    end

    @neg_plan_predicates.each do |name|
        negative_sets << index.send(PLAN_PREDICATES.fetch(name))
    end

    [positive_sets, negative_sets]
end

#mission ⇒ Object

Matches if the task is a mission



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# File 'lib/roby/queries/task_matcher.rb', line 381

def mission
    add_plan_predicate :mission_task?
end

#negate ⇒ Object

Negates this predicate

The returned task matcher will yield tasks that are not matched by self



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# File 'lib/roby/queries/task_matcher.rb', line 648

def negate
    NotMatcher::Tasks.new(self)
end

#not_mission ⇒ Object

Matches if the task is not a mission



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# File 'lib/roby/queries/task_matcher.rb', line 386

def not_mission
    add_neg_plan_predicate :mission_task?
end

#not_permanent ⇒ Object

Matches if the task is not permanent



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# File 'lib/roby/queries/task_matcher.rb', line 398

def not_permanent
    add_neg_plan_predicate :permanent_task?
end

#permanent ⇒ Object

Matches if the task is permanent



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# File 'lib/roby/queries/task_matcher.rb', line 393

def permanent
    add_plan_predicate :permanent_task?
end

#respond_to_missing?(m, include_private) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/roby/queries/task_matcher.rb', line 539

def respond_to_missing?(m, include_private)
    m.to_s.end_with?("_event") || super
end

#roots(plan, in_relation) ⇒ #each_in_plan

Filters tasks which have no parents in the query itself.

Will filter out tasks which have parents in relation that are included in the query result.

Returns:



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# File 'lib/roby/queries/task_matcher.rb', line 597

def roots(plan, in_relation)
    evaluate(plan).roots(in_relation)
    self
end

#to_s ⇒ Object 



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# File 'lib/roby/queries/task_matcher.rb', line 51

def to_s
    result = super
    unless arguments.empty?
        args_to_s = arguments.map { |k, v| ":#{k} => #{v}" }.join(", ")
        result << ".with_arguments(#{args_to_s})"
    end
    result
end

#which_fullfills(model, arguments = nil) ⇒ Object

Filters on task model and arguments

Will match if the task is an instance of model or one of its subclasses, and if parts of its arguments are the ones provided. Set arguments to nil if you don’t want to filter on arguments.



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# File 'lib/roby/queries/task_matcher.rb', line 65

def which_fullfills(model, arguments = nil)
    with_model(model)
    with_model_arguments(arguments) if arguments
    self
end

#with_arguments(arguments) ⇒ Object

Filters on the arguments that are declared in the model

Will match if the task arguments for which there is a value in arguments are set to that very value. Unlike #with_model_arguments, all values set in arguments are considered.

See also #with_model_arguments

Example:

class TaskModel < Roby::Task
  argument :a
  argument :b
end
task = TaskModel.new(a: 10, b: 20)

# Matches on :a, :b is ignored altogether
TaskMatcher.new.
    with_arguments(a: 10) === task # => true
# Looks for both :a and :b
TaskMatcher.new.
    with_arguments(a: 10, b: 30) === task # => false
# Looks for both :a and :c, even though :c is not declared in TaskModel
TaskMatcher.new.
    with_arguments(a: 10, c: 30) === task # => false



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# File 'lib/roby/queries/task_matcher.rb', line 135

def with_arguments(arguments)
    @arguments ||= {}
    @indexed_query = false
    self.arguments.merge!(arguments) do |k, old, new|
        if old != new
            raise ArgumentError,
                  "a constraint has already been set on the #{k} argument"
        end
        old
    end
    self
end

#with_model_arguments(arguments) ⇒ Object

Filters on the arguments that are declared in the model

Will match if the task arguments for which there is a value in arguments are set to that very value, only looking at arguments that are defined in the model set by #with_model.

See also #with_arguments

Example:

class TaskModel < Roby::Task
  argument :a
  argument :b
end
task = TaskModel.new(a: 10, b: 20)

# Matches on :a, :b is ignored altogether
TaskMatcher.new.
    with_model(TaskModel).
    with_model_arguments(a: 10) === task # => true
# Looks for both :a and :b
TaskMatcher.new.
    with_model(TaskModel).
    with_model_arguments(a: 10, b: 30) === task # => false
# Matches on :a, :c is ignored as it is not an argument of +TaskModel+
TaskMatcher.new.
    with_model(TaskModel).
    with_model_arguments(a: 10, c: 30) === task # => true

In general, one would use #which_fullfills, which sets both the model and the model arguments



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# File 'lib/roby/queries/task_matcher.rb', line 102

def with_model_arguments(arguments)
    valid_arguments = model.inject([]) do |set, model|
        set | model.arguments.to_a
    end
    with_arguments(arguments.slice(*valid_arguments))
    self
end

#|(other) ⇒ Object

Computes the union of two predicates

The returned task matcher will yield tasks that are matched by any of its the elements.

Roby does only supports computing the OR of task matchers (cannot combine different operators)



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# File 'lib/roby/queries/task_matcher.rb', line 609

def |(other)
    result = OrMatcher::Tasks.new
    result << self
    case other
    when OrMatcher::Tasks
        result.merge(other)
    when TaskMatcher
        result << other
    else
        raise ArgumentError,
              "cannot compute the union of a TaskMatcher with #{other}"
    end
end